Hood latch



3 SheetsSheet 1 E. D. DALL HOOD LATCH May 12, 1959 Filed July i i, 1955 Edward D D6122 E. D. .DALL

HOOD LATCH May 12, 1959 S Sheets-Sheet 3 Filed July 8, 1955 United States Patent HOOD LATCH Edward D. Dall, Birmingham, Mich., assiguor to Atwood Vacuum Machine Company, Rockford, 111., a corporation of Illinois Application July 8, 1955, Serial No. 520,725

Claims. (Cl. 292-6) This invention relates to hood latch structures specially designed for use in latching the liftable hood enclosing the engine of a motor vehicle to lock said hood releasably but securely in closed position.

The hood latch of my invention includes a safety catch which positively prevents the hood opening up accidentally in the event it has not been closed fully to begin with, the safety catch being releasable only when the manually operable release lever has been moved to a retracted position with respect to a tail portion of said safety catch, the hood latch also including a latch lever releasable in a similar way by the release lever and designed to take hold equally well whether the hood is closed fully or only partially, said latch lever incorporating a ratchet portion designed not only to hold the hood securely in whatever position it is left in when closed but also to allow the hood to be closed further by hand or by gravitation with the car in motion and resume the same good hold in each new position.

Another important feature of the present hood latch structure'is that although tension springs are provided in connection with the safety catch and latch lever, as well as in connection with the release lever, and the hood latch structure will, of course, operate to best advantage when these three springs are all intact, the structure will not be inoperative if one or more of the springs breaks, and it is, of course, a simple matter to replace any one or more of the springs should that ever become necessary.

The invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a front elevation of a hood latch structure made in accordance with my. invention, showing the parts in what corresponds to the closed position of the hood, portions of, the mounting bracket and keeper being broken away and indicated by dot and dash lines, for purposes of better illustration;

Fig. 2 is a phantom side view of Fig. 1, showing the hood attached bracket in dot and dash lines, while showing the other parts in full lines;

Fig. 2a is;a fragmentary side view related to Fig. 2, showing the hood attached bracket and other parts in full lines and the release lever in dot and dash lines, so as to better illustrate the range of movement of the protruding ends of the safety, catch and latch lever in the slot in said bracket, and at the same time show how the notch in the release lever cooperates with these protruding ends;

Fig. 3 is anisolated front view of the safety catch;

Fig. 4 is an isolated front view of the latch lever;

Figs. 5 and 6 are, two isolated views of the manually operable release lever, looking at it from the front and side, respectively;

L Figs. ,7 and 8 are two views of the hood lock latch nvet;

Fig. 9 is a front-view of the spacer washer, and

Fig. 10 is a top view of Fig. 1.

The same-reference numberals are applied to corresponding parts throughout the views.

Referring to the drawings, the keeper bracket indicated Patented May 12, 1959 at K and adapted to be attached to the body, is formed in dies from a single piece of sheet metal to provide a vertical portion 10 from the upper end of which a horizontal portion 11 extends at right angles. Both portions are reinforced by side edge flanges as shown. The horizontal portion 11 has a rectangular opening 12 provided therein, at opposite sides of which flanges 13 extend downwardly as shown. The vertical portion 10 preferably has one or more vertical slots 14 provided therein to receive bolts 15 for mounting the keeper on a fixed vertical portion 16 of the grille or radiator housing at the front end of the automobile, such mounting permitting adjustment of the keeper in relation to the latch structure L that is mounted on the front end of the raiseble hood of the automobile provided as an enclosure for the engine in the usual way. However, adjustment of keeper K is not actually necessary because the latch structure L is self-adjusting. Opening 12 may be provided in the grille or lower hood reinforcement.

The latch structure L comprises a stamped sheet metal bracket 17 adapted to be attached to the hood, said bracket providing laterally spaced, substantially parallel side walls or flanges 18 and 19, bent rearwardly substantially at right angles from a front web portion 20. The lower end of the web 20 has rearwardly bent, horizontal attaching flanges 21 for connection by means of bolts or the like to a horizontal flange 22 that is located underneath and provided on the front end portion of the hood. The web 20 also has a generally rectangular pilot extension 23 integral therewith and extending downwardly therefrom for reception in the opening 12 in the top of the keeper K. The lower end of the extension 23 is rounded and tapered, as shown in Fig. 1, for easier entry in opening 12 and is reinforced along its lower end and along its vertical side edges, as indicated at 24, the upper ends of these flanges 24 merging with the flanges 21, as indicated at 25 in Fig. 1. There is preferably an elongated embossed portion 26 pressed from the pilot extension 23 rearwardly to provide a flat bearing surface on the back thereof for slidable engagement by the latch lever 27, and there is also integral with one side flange 24 of the pilot extension 23 near the lower end thereof an L-shaped hook extension 28, which serves as a limit stop for the safety catch 29 and as a guide in spaced relation to the embossed portion 26 to keep the safety catch 29 in the proper close relationship to the pilot extension 23, and, by so doing, also maintain the latch lever 27 in the correct relationship to said pilot extension. The latch lever 27 and safety catch 29 are both slidably pivotally mounted on the bracket 17 on a rivet 30 that is mounted by means of its reduced D-shaped shank end 31 in a D-shaped hole 32 provided in the web portion 20 of the bracket 17. The shank 31 is entered in the hole 32 from behind the web 20 and its protruding end portion is upset, as indicated at 33 in Fig. 2, to make the rivet 30 rigid with the bracket 17. A washer 34 having a D-shaped center hole 35 to accommodate the shank 31 is also riveted in place against the back of the web 20 of the bracket 17 when the rivet 30 is applied to the bracket, this washer keeping the latch lever 27 spaced from the web 20 so that it rides by means of its slot 36 on the slightly reduced intermediate portion 37 of the shank of the rivet 30 and so that the longitudinal upwardly directed rib. 38 that is provided on this portion will'cooperate properly with the sawtoothed upper edge 39 of the slot 36. The latch lever 27 serves thereto, as clearly appears in Fig. 1, this spring having its one end 44 anchored to the side flange 19 of bracket 17 and its other end 45 anchored on a laterally reaching tail extension 46 of the latch lever 27, whereby to urge the latch lever 27 normally in a clockwise direction with respect to rivet 30, as said lever is seen in Fig. 1. Moreover, the slot 36 in lever 27 is slightly wider than the shank portion 37 combined with the rib 38 so as to enable the sawtooth edge 39 of slot 36 to be released from rib 38 and thereby permit lever 27 to also be displaced laterally to the left as viewed in Fig. 1 along the shank portion 37 of the rivet 30 by the force present in tension spring 43. The lateral displacement of the slot 36 in lever 27 along the shank 37 is determined by the extent to which the latch lever 27 enters opening 12 in the keeper K. The further downward the lever 27 moves, the more it will be enabled to shift to the left because of the inclined surface portion 64 which bears against the left side flange 13 in opening 12. Consequently, the greater the downward force applied to the hood when closing it against its counterbalancing springs which always tend to raise the hood, the further the slot 36 will move toward the left and the tighter will become the hood latch. After the closing pressure on the hood has been released, the lever 27 may tend to rise slightly but due to the inclined surface 64 bearing against the flanged edge 13 of the keeper opening 12, a downward force component will be established on lever 27 thus securely engaging the rib 38 with the related tooth 39 on slot 36 and thus securely fastening the hood down. It is appropriate to call attention at this point to the fact that even in the absence of the spring 43, as where the spring breaks, the latch lever 27 tends to swing by gravity in a clockwise direction relative to rivet 30. Another coiled tension spring 48 is connected at one end to an ear 49 on safety catch 29, as indicated at 50, and has its other end 51 anchored to the side flange 19 of bracket 17, and this spring, which is stretched similarly as spring 43, tends normally to urge the safety catch 29 to move in a counterclockwise direction about the rivet 30 as a center to the position shown in Fig. 1. However, when the toe portion 67 of lever 29 is released by actuating the release lever 55 and the hood is raised thus drawing the pilot extension 23, hook extension 28, the latch lever 27 and safety catch lever 29 upward, the downwardly inclined strike surface 68 at the lower end of lever 29 will ultimately engage the flange 13 at the edge of opening 12 in the keeper bracket K thus causing the safety catch lever to rotate in a clockwise direction away from the stop surface provided by the hook extension 28 and further stretching spring 48 as it continues its upward movement. As soon as the lower toe portion of the safety catch lever 29 clears the opening 12, spring 48 will then cause lever 29 to move back to the position shown in Fig. 1 against stop 28. However, in the event the spring 48 breaks the laterally reaching tail extension 52, which extends through a slot 53 in the side flange 18 of bracket 17 and engages the shoulder 54 on the release lever 55, that is pivoted, as indicated at 56, to the outer side of the side flange 18, will serve as a fulcrum for the safety catch 29 to insure counterclockwise movement relative to rivet 30, the inclination of the slot 42 being correct for such operation, as is apparent in Fig. 1. A coiled tension spring 57 is connected by its lower end 58 to the rear end of the release lever 55, as shown in Fig. 2, this spring being stretched and anchored at its upper end 59 to the side flange 18 of bracket 17 to urge the release lever normally in a counterclockwise direction, as viewed in Fig. 2, such movement being limited by engagement of the upwardly extending rear portion 60 of the lever with the back of the tail extension 52 of the safety catch 29, as appears in Figs. 2 and 2a. The release lever 55 is operated manually by means of its forwardly reaching downwardly curved handle portion 61. Here again, if the spring 57 should break it is apparent that the release lever will, nevertheless, function reasonably well because it can depend upon gravity to swing in a counterclockwise direction about the rivet 56 as a center.

In operation, the hood is adapted to be lifted by hand at its front end and has at its rear end a hinge connection with the automobile body in the usual way, spring means being also provided to counterbalance the weight of the hood to make it easier to raise it and hold it in raised position if the hood is unbalanced enough so that it will drop to closed position when released. When the hood is dropped to close it, the latch structure L automatically locks the hood by cooperation with keeper K. The handle portion 61 of the release lever 55 is raised preliminary to the lifting of the front end of the hood, and in this operation the release lever 55 is turned in a clockwise direction, as viewed in Figs. 2, 2a, and 6, against the action of spring 57 to free the ends of the tail extensions 47 and 52 from the notch 62 provided in the upwardly extending rear portion 60 of the release lever 55, so that there is nothing to interfere with the freedom of movement of the latch lever 27 and safety catch 29, and they will slide freely through the opening 12 in the keeper K as the hood is raised. In the closed position of the hood, the pilot 23 with the lower end portions of the safety catch 29 and latch lever 27, extends downwardly through the opening 12 in the keeper K. In closing, the safety catch 29 and pilot extension 23 ride into the opening 12 past the curled flanges 13, followed by the latch lever 27, and these parts ride in place underneath the flanges 13. The parts are shown in closed position in Fig. 1 with the hooked end 68 of the safety catch 29 in place directly below the flange 13 on one side of the opening 12 while the inclined latch surface 64 provided on the outer side edge of the latch lever 27 is disposed all the way down under the flange 13 on the other side of the opening. If the hood is not closed tightly the inclined latch surface 64 is only partway down under flange 13 and, because of this, the hood is securely held against opening any further, the sawtoothed upper edge 39 of slot 36 engaging the rib 38 on rivet 30 serving to lock the latch lever 27 against movement of the lever bodily to the right, as would be necessary for hood opening movement, while the spring 43 pulling downwardly and to the left on latch lever 27 below the rivet 30 serves to insure continued good engagement of the sawtoothed edge 39 with the rib 38 and tends to urge the latch lever 27 bodily to the left and in a clockwise direction about the rivet 30 as a center. Hence, if the hood in the running of the car tends to gravitate toward a more nearly closed position, everything is in favor of the latch lever 27 shifting in the direction of its holding the hood more tightly closed, rather than allowing it to open any wider.

Considering first in more detail the functioning of latch lever 27 by itself and without its companion safety catch 29, it will be seen by reference to Figs. 1 and 4 that when the release lever 55 is moved to retracted position so that there is nothing to interfere with freedom of movement of the latch lever 27 about the rivet 30 as a center, the hood can be raised freely, because in such movement of the hood the tail extension 47 of lever 27 can swing upwardly in the counterclockwise movement of lever 27 about rivet 30 as a center as the inclined latch surface 64 rides on the curled flange 13 on the left side of the opening 12 in keeper K, spring 43 stretching a little more to allow this movement of the latch lever 27. In the closing of the-hood, release lever 55 is held in its operative positive by its spring 57 while the outer end of the tail extension 47 projecting through slot 53 in flange 18 is engaged in notch 62 so that the latch lever 27 fulcrums about and slides on this outer end portion of the tail extensions 47 when the inclined strike surface 66 on the bottomof the lever 27 (which is substantially in crosswise relation to the inclined slot 36, as best appears in Fig. 4) rides on the rounded top of the flange 13 on theleft hand side of the opening 12 in keeper K as the hooked end of the latch lever 27 enters the-opening 12. As a result, rivet 30 rides along the smooth bottom edge of slot 36 whichis inclined downwardly and away from the tail extension 47 as the latch lever 27 moves bodily to the right against the resistance of spring 43 until the hooked lower end of the lever 27 rides down under the flange 13. Then, assuming the hood has been closed hard enough, the inclined latch surface 64 on the outer side edge of the latch lever slides all the way down to the extent illustrated in Fig. 1 so that rivet 30 is all the way to the inner end of slot 36, whereupon, partly by gravity and partly by virtue of spring 43, latch lever 27 takes a positive hold on rivet 30 by means of the sawtoothed edge 39 of slot 36 engaging rib 38, as appears in Fig. 1. If the hood is not slammed shut but is closed only lightly, the chances are that the rib 38 will occupy a position one, two or three teeth from the inner end of sawtoothed edge 39 and the inclined latch surface 64 will accordingly not be all the way in under flange 13. If the hood is closed too lightly so that the rib 38 occupies a position near the middle of the sawtoothed edge 39 or even farther toward the outer end of slot 36, the chances are that motion of the hood in the running of the car will be enough to cause the hood to gravitate toward a more nearly fully closed position and when that occurs the release lever 27 will shift its position in relation to rivet 30 automatically so that the rib 38 will wind up in a position much nearer the inner end of the sawtoothed edge 39. Leaving the safety catch 29 out of consideration regardless of how lightly the hood is closed, so long as the inclined latch surface 64 is engaged under the flange 13 to any extent at all, there is no danger of the hood swinging open under wind pressure while the car is running, because the teeth 39 engaging rib 38 positively prevent such movement of latch lever 27 as would be required for the hood to open. In passing, attention is called to the fact that the teeth 39 have their sides a at the same angle as the latch surface 64, as best appears in Fig. 4, while the rib 38 on rivet 30 is disposed, as appears in Fig. 1, at right angles to the sides a of the teeth. Hence, whenever the latch lever 27 is disposed with its latch surface 64 not quite all the way down under flange 13 on the left side of opening 12 in keeper K, any downward movement of the hood, if suflicient to allow the rib 38 to shift to the next tooth 39 inward, or farther, will be accompanied by the rib 38 disengaging the teeth 39 while rivet 30 pressing downwardly on the smooth lower side of slot.

36 forces the lever 27 downwardly and the lever, under action of spring 43 and guided by its latch surface 64, shifts relative to rib 38 for the latter to take hold farther inward on the toothed side 39 of slot 36.

Considering next the safety catch 29 in greater detail itself, referring to Figs. 1 and 3, when the release lever 55 is moved to retracted position against the action of spring 57 in the raising of the hood, the outer end portion 67 of the tail extension 52 is released from notch 62 and shoulder 54 of lever 55 and the catch 29 is accordingly free to swing clockwise about the rivet 30 as a center, and hence, when the hooked lower end 68 of the catch encounters the flange 13 in a hood raising direction there is nothing but spring 48 to interfere with the catch turning clockwise about rivet 30 as a center, the spring 48 stretching enough to allow the catch 29 to ride easily from under the flange 13 and out of opening 12. In the closing of the hood, the inclination of the strike surface 69 on the bottom of the catch (which is substantially in crosswise relation to the inclined slot 42, as best appears in Fig. 3) plays an important part in camming the lower end of the catch to the left as it rides on the rounded top of the flange 13 and down into opening 12, the L-shaped hook extension 28 on the pilot 23 insuring proper positioning of the hooked end 68 of the catch in relation to the opening 12 and flange 13 to insure the correct camming action. The catch 29 fulcrums about and slides on the outer end 67 of its tail extension 52 in the slot 53 in flange 18 as the catch moves bodily upwardly and to the left on rivet 30 as permitted by the slot 42 provided in said catch until the hooked end 68 on the lower end of the catch rides under the flange 13. Once the hooked end 68 of the catch is down under the flange 13 there is no danger whatever of the hood being thrown open accidentally, because the shoulder 54 on the release lever 55 which serves as the fulcrum for the catch in its downward movement toward closed position stands in the way of allowing the end 67 to swing downwardly to the extent that is necessary for the hooked end 68 to ride out from under the flange 13 on the right side of opening 12 in keeper K, and it is only when the release lever 55 is moved to retracted position preparatory to the lifting of the hood that this shoulder 54 is out of the way of the end 67 of the tail extension 52, as should be clear from inspection of Figs. 2 and 2a.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

I claim:

1. Latch mechanism for a pivotally mounted closure member such as an engine hood of an automobile comprising a vertically disposed support plate adapted to be attached to said closure member, a pivot pin secured to said support plate and extending normal to the plane of said plate, an upwardly directed rib on said pivot pin, a generally vertical latch lever parallel with said support plate, said lever having at its upper end a tail portion reaching laterally in one direction and a slotted portion reaching laterally in the opposite direction from said tail portion, said slot being inclined and directed downwardly and away from said tail portion, said slot being wider than the thickness of said pivot pin and through which said pivot pin extends to form a pivot axis for rotation of said latch lever as well as sliding movement thereof, the lower edge of said slot being smooth for sliding engagement with the underside of said pivot pin and the upper edge of said slot being toothed for ratchet engagement with said rib on said pivot pin, said latch lever including a depending portion disposed intermediate said tail portion and said slotted portion and extending downwardly, one side of said depending portion being provided with a downwardly inclined latch surface adapted to elfect a sliding dogging engagement with one side of an opening in a stationary keeper following entry of said depending portion therein, the lower end of said depending portion being provided with a strike surface inchned in a direction substantially cross-wise to the longitudinal direction of said slot and which becomes engaged with the side of said keeper opening upon initial entry to efl ect a sliding movement of said latch lever and slot along said pivot pin, spring means biasing said latch lever such that said inclined latch surface is urged against one side of the opening in said keeper member thereby to increase the dogging action and movement of the uppermost end of said slot toward said pivot pin, the reaction between said inclined latch surface and said one side of said keeper opening effecting a pivotal movement of said latch lever about said tail portion thereof to cause engagement between said rib on said pivot pin and the tooth in said slot nearest thereto, and manually operable release means mounted on said support plate for detachably holding engagement with the outer end of said tail portion to prevent said latch lever from pivotal movement in a direction such as would effect release of said inclined latch surface from the edge of said keeper opening.

2. A latch mechanism as defined in claim 1 wherein said tooth on said pivot pin is of rectangular form at the outer end thereof and said teeth along the upper side of said latch lever slot have their sides disposed in right angle relationship to each other, one side of each of said teeth along said slot and the corresponding abutting side of said tooth on said pivot pin being inclined in planes generally parallel to said downwardly inclined latch surface on said latch lever.

3. Latch mechanism as set forth in claim 1 including a generally vertical safety catch parallel to said latch lever and pivotally and slidably mounted at its upper end on said pivot pin, said catch including a depending portion longer than said depending portion on said latch lever and having a laterally extending projection on its lower end on the bottom of which is a strike surface inclined in a direction substantially crosswise relative to the strike surface on the lower end of the latch lever for camming engagement on the other side of the opening in the keeper, said catch having a slot provided therein at its pivotal connection to said support that is inclined in a direction substantially crosswise relative to the slot in the latch lever permitting sliding as well as pivotal movement of said catch, said catch having on its upper end a laterally reaching tail extension arranged to be detachably engaged and held at its outer end by said manually operable release means, and a tension spring stretched between an anchor point on said support plate and said catch above said pivot pin urging said catch to move downwardly and to turn in the opposite direction to said latch lever about said pivot pin.

4. Latch mechanism as set forth in claim 3 and which further includes a pilot extension depending from said support plate parallel with said latch lever and catch, and a stop on said pilot extension engaged by said safety catch and limiting the turning movement thereof effected by said tension spring.

5. Latch mechanism as set forth in claim 3 and which further includes stop means on said support plate engaged by said safety catch and limiting the turning movement thereof effected by said tension spring.

References Cited in the file of this patent UNITED STATES PATENTS 909,561 Dolcater r Jan. 12, 1909 2,658,778 Dall -r Nov. 10, 1953 2,698,762 Dall Ian. 4, 1955 

